Pol eta focal recruitment to damaged DNA sites efficiently takes place in permanently arrested cells

SORIA G, ESSERS J, KANAAR R AND GOTTIFREDI V

Rotterdam-Holanda.

Congreso; Third Annual Review Meeting; 2008

DNA Repair Network

The activity of Pol η on translesion DNA synthesis (TLS) has been extensively characterized. Until now is not certain if Pol η function on TLS is restricted to the replication fork itself or has a delayed activity filling the gaps that remain due to the incapacity of replication polymerases to synthesizes across damaged-DNA distortions.  Moreover, recent reports suggest that pol η could be involved in the Homologous recombination process (HR). However, all the functions of Pol eta described so far require S-phase occurrence, since non TLS or HR events are expected to take place in the G1 stage of the cell cycle. Using the CDKs inhibitor, p21, and different cell-cycle stage markers combined with a range of single cells analysis and sub-nuclear damage methods we reveal that focal recruitment of Pol η to damaged sites takes place with similar efficiency in both G1/G2 and S-phase cells. Taken together, these data discloses the possibility of a new non-described function of Pol η that may contribute to understand its complex behaviour and regulation, and also put forward a way to dissect the study of cell cycle-dependent DNA repair-proteins activities.